1. Field of the Invention
The present invention relates to a novel biologically active polypeptide, method of obtaining same as well as use thereof. The polypeptide is obtained through a cultivation of an insect cell and more particularly a cell line established from flesh fly (Sarcophaga peregrina) embryo.
2. Related Arts
It has been known that a certain antibacterial substance will appear in a body fluid, when a vaccine is inoculated to an invertebrate such as insecta ["Eur. J. Biochem." Vol. 106, page 7 (1980)].
The present inventor has also found such a fact on the Sarcophaga peregrina that a certain antibacterial polypeptide appears in its body fluid, when a larva of the insect is injured in its body, the polypeptide being separated and purified to investigate its physicochemical properties [see Jap. Pat. Nos. 59-13730 (A) published Jan. 24, 1984 and 61-122299 (A) published Jun. 10, 1986].
Since the polypeptide produced by the insect shows a wide antibacterial spectrum, almost no toxicity and is a protein, the substance has been expected to be an edible antibiotic but has difficulties in its production, including difficulties relating to obtaining the raw material (the insect per se), isolation and purification thereof.